diff --git a/calendar/classes/local/event/forms/eventtype.php b/calendar/classes/local/event/forms/eventtype.php
index c5884d8031f..2e0ae72b81a 100644
--- a/calendar/classes/local/event/forms/eventtype.php
+++ b/calendar/classes/local/event/forms/eventtype.php
@@ -78,7 +78,8 @@ trait eventtype {
         if (!empty($eventtypes['user']) && count($options) == 1) {
             $mform->addElement('hidden', 'eventtype');
             $mform->setType('eventtype', PARAM_TEXT);
-            $mform->setDefault('eventtype', 'user');
+            $mform->hardFreeze('eventtype');
+            $mform->setConstant('eventtype', 'user');
             return;
         } else {
             $mform->addElement('select', 'eventtype', get_string('eventkind', 'calendar'), $options);
diff --git a/calendar/classes/local/event/forms/managesubscriptions.php b/calendar/classes/local/event/forms/managesubscriptions.php
index b228914e087..4cc4cf270cd 100644
--- a/calendar/classes/local/event/forms/managesubscriptions.php
+++ b/calendar/classes/local/event/forms/managesubscriptions.php
@@ -106,7 +106,7 @@ class managesubscriptions extends \moodleform {
         $courseid = (!empty($data[$coursekey])) ? $data[$coursekey] : null;
         $eventtypes = calendar_get_allowed_event_types($courseid);
 
-        if (empty($eventtype) || !isset($eventtypes[$eventtype])) {
+        if (empty($eventtype) || !isset($eventtypes[$eventtype]) || $eventtypes[$eventtype] == false) {
             $errors['eventtype'] = get_string('invalideventtype', 'calendar');
         }